AP Chapter 3 Guide
Introduction: Chapter 3 deals with the fundamental unit of measurement in chemistry, the mole. The Law of Conservation of Mass is the unifying principle of the chapter. The chapter deals with compounds and then with reactions and equations.
A key point in the chapter is the convenience of the mole as a unit. Chemical reactions and formulas and the structures of molecules all focus on numbers of atoms, molecules, or ions. These particles are so small we can't see them, and so plentiful we can't count them. But the MOLE provides a unit that allows us to connect the number of atoms (the thing we are interested in knowing) to something we can measure (such as mass).
Learning Goals for the chapter - successful mastery of this chapter means you are able
Section 1: to describe the modern atomic mass scale and explain how atomic masses are determined experimentally
Section 2: to explain the importance of the mole concept and show how to convert among moles, mass, and the number of particles for a given sample
Section 3: to calculate values for molar mass and convert units for compounds
Section 4: to calculate the mass percent of a given element in a compound
Section 5: to utilize mass information to calculate the empirical and/or molecular formula for a compound
Section 6: to discuss the characteristics of a chemical reaction, based on information given in a balanced chemical equation
Section 7: to write a balanced chemical equation, given information about reactants and products
Section 8: to calculate masses of reacting chemicals, based on the balanced equation
Section 9: to determine the identity of the limiting reactant in a specific reaction, and perform stoichiometric calculations based on the limiting reactant.